Testing system



' 1 2 June 14 1927' J. lw.- VAN DE 4WATER ET AL. 63 048 TESTING SYSTEM A Filed Jan. 16,' 192.5' 2 sheets-sheet 1 4; 42 j W 4f .J7/MW Vande v10/en #7W/fm ef/M/a/r.

June 1'4 1927. 1,632,048

J. w. VAN DE WATER E1- AL f TESTING SYSTEM," y

Filedl Jan. 16,l L92@ 2 sheets-sheet 2 Vcircuits isl yprevented.A

Patented June 14, 1927.

` 1,632,04a UNITED STATES eAieNroFFicE.

JOHN W. VAN DE VATER, OF HASTINGS-ON-THE-HUDSON, AND BERT R. `BLIRLVGF JACKSON HEIGHTS, NEW YORK, .ASSIGNORS T0 WESTERN ELECTRIC COMPANY, IN-

CORPORATED, OF NEW YORK, N. Y., A CORPORATIONAOF NEW `YORK TESTING sYsiiiiir.V

Appiication filed January 16,1926,"- serial Nd.' 81,665.

rIhis invention relates to testing systems, and particularly to an improved arrangement for. testing the operatinkir characteris- 'tics of various typesof answering jacks and their associated linev circuit apparatus, and

is an improvement of the testing system dis-` closed in the patent to Lawson et `al., No.`

1,617,336, granted VFebruary l5, 1927.

In the testing system, as disclosed in the above mentioned patent, there are ineans n the above type by including in a single test set means for testingr and measuring the offici-ating characteristics of a Vplurality of different types of answeriiigjach circuits and their associated apparatus andfor further observing; and analyzing uiistandard,

con litions that may arise in suoli various f les of 'jack circuits and theiry associated paratus. t

it, feature of this inventionis the provision of ,means whereby not only operatingl tesis in crordance with the above mentioned system may be performed, but alsofto provide anditional equipments when-)by 'so-called f adjustment tests may be performed. That is, .means is provided whereby the act-ual op'- cratingi' and release characteristics of the cuto and line relays ofthe jack circuitsunder test may be determined and Vwhereby the values of theseelectrical characteristics may be measured. :T

inother feature of the invention is the provision of means ina testing system of the above type whereby, in addition to the coutinuitytests Vof thetiplconductorsI of the jack circuits, there Vmavbe i'letern'nned whetheroi not 'the characteristics ofv the elcctrical circuit vthrough the ,tip conductors are above'or below a certain predetermined value and whereby if the electrical characteristics are below the predetermined value ythe continuing of the testing is an object of this invention to im prove and extend the utility of systems ofV of ,thefsucceeding jack Another feature is the provision in the system of the above type of means whereby the automatictest of any particular jack circuit may bev inadeto the exclusion of the testing of any of the other circuits. ySuch means may be controlled from the handles or holders of the multiple Aplugs used for connecting a group of answering jacks with f thejacks of 'the test set. 1

` Another feature isthe provision in a sys tem ofthe above type yof means whereby if the standard sleeve'circuit tests are not suc cessful, the nature and origin of the iincuits may ,be determined. c Y

Another feature is the provision of means whereby special answering ]ack,circuits may standard conditions occurring in these cirbe tested, such for example, as those that' have'a direct ground on the tip conductor or jack circuits that are associated with-subscribers lines equipped with coin-collecting` apparatus. Y tion is the provision of various signalling means in testing` systems of this type such as, for example: an audible Ysignal that operates after thetests ofV all ofthe answeringv jacks in a group4 have been successfully coin plete/d; visual signals `for indicating whether an adpistment test of a line vrelay or a continuity test of a .jack circuit is being' per-` formed Y whether or not the electrical characteristics of the sleeve circuitsare below or above a and visual' `signals to indicate certain predetermined value;

Other features for analyzing unstandardr conditions are provided by thisginvention suclias, `means for detecting a ground be-y Aaroundy or battery onv the tip or ring confy ductors. e

l Another feature is the provision of means including an artificial line whereby the r1 tiouing of the test met itself may be h Another "feature Aof the inven This .inventionwill bcdescribed with the 'Y aid. of the accompanying` drawings in which Fig. l illustrates a circuit for (a. test setranged in accordance with this invention and Figi.` 2` illustrates .a plurality of 'answering ,jacksvr toi'be tested, onexof whichhas been shownvwith litsessentialline and cut-off re` V layswired inac ordance with the usualv wir-vr ing of standard circuits of this type. There is also shown in this figure a multiple contact case for connecting;d the jacks forming part or the test set with the said answering jacks. For this figure there is also shown a plurality of other jacks and circuits includine an artificial line arrangement, beingr part of the test set whereby the test set itself may be tested. Fig. 3 illustrates the wiring of one of a plurality ot another type of answering jack that may be tested by this set while Fig. l illustrates the wiring,r of athird type of answering` jacks that may be tested by this set, namely, a j acl; associated with a subscribers line and equipped'for coin collecting service.

Reterring now to the drawings a test set is illustrated therein arranged for the testing of tive answeringv jack circuits at ogo t'me. without shitting' the manual connections between the set and the live answerin,f;` jacks.' To this end, the set is provided with tive` jacks 1 to 5 into which the individual. plugs G to are arranged single holder 11 may be respectively and simultaneously inserted. The conductors et these plugs G toll) ma)v be arranged in a single cord 12 and may terminate at the opposite end in corresponding plugs 13 to 17 arranged in a sinfile holder 18. The plugs 18 to 17 are theretore similarly adapted to be inserted simultaneously into live answering jacks to be tested such as jacks 19 to 23. The circuit for jack 19 and its associa-ted line and cut-ott relays have been shown in detail. Associated with jacks 1 to 5, are signal lamps 2li to 28- which are arranged witha plurality oi other signal lamps such as y to in the test set to variously indicate the progress and outcome oit the different tests performed by the set as will hereinafter be described. To automatically advance the testing trom one answering jack circuit to another there is provided a ,series ot automatically operatingrotary switches to L l0 which may be actuated by the stepping magnet i1 to advance the brush contact thereof one step at the time to establish connection with one set of terminals after another. To start the test set operations and to manipulate it to perform a number of different tests, a series ot manually operated keys are provided. These keys are numbered l2 to 55. Other circuit connections during the testing` operations are performed by a plurality of relays, such as 57 to 69. A resistance 70 and three adjustable resistance?. 71 to 73 and a milliamineter 7d are other apparatus provided in this set for' checking' the electrical characteristics of the circuits to be tested as willV hereinatterbe described. j

To bring` out the Various features ofthe invention as embodied in this test set, a description will now be made of the various tests that may be performed thereby.

These tests may bei described as operating and adjustment tests ot' the cut-off and line relays of five answering jack circuit-s and may be divided into three groups. The first is the operation or continuity tests of the answering' jack conductors and the second is the adjustment tests oit the cut-off relays while the third is the adj ustmcnt tests of the line relays, the last two tests relating to the checking and measuring the operating characteristics of cut-off and line relays.

To enable the test set to peror'm these. tests, jacks 1 to 5 are connected through to j ach's 19 to 23, respectively, by means of the cord 12, and to start-the vcontinuity tests key 52 is operated. The operation of this key closes a circuit tor relay 57 as follows: battery, winding of stepping magnet l1, armature and back contact ot this stepping mag'- net, normal mahe-bci'orebreal; contacts of relays (S7 and G6, lett-hand armature and baci; contact o1' relay 58, winding,r ot' relay 57, contacts ot hey to ground, Relay 57 operates in this circuit and closes circuits through from the line relay associated with jack 19 as follows: one circuit from ground, lett-hand winding,r of line relay 100, inner right armature and bach contact ol cut-oil relay 101, tip terminals of jack-19, plug 13, plu" (3, jack 1, to the corresponding terminal and the brush ot switch a closed pair ot contacts ot leys 416, @t5 and e3, outer right-hand armature and front contact o'l" rclay 57, windings of relays 59 and G() in series to battery. Another circuit 'from battery, right-hand' winding of line relay`100, ring Contact of jack 19, plug 13, plug jaelr 1 corresponding terminal and brush of switch 36, a closed pair ot' contacts of keys 46, 44, anda-3, inner right-hand armature and front contact of relay 57, winding of relay G1 to. ground. It' the line relay 100 is in a standard condition, relay 59 operates in the first traced circuit but relay GO does not opere e. as it is marginal and does not respond if the characteristics ot this circuit are normal. The operation of relay 59 closes an obvious circuit tor lighting,v o t signal lamp 30, which thus indicates that a circuit ofV standard character is closed lthrough the line relay 100 and the tip conductor ot the circuits lor answering acl; 19. The'operation of relay 59 also closes an obvious circuit through the upper winding of relay (5;, causing the oper tion oi this relay. The operation o't relay 59 also closes partly acircuit for the ,upper winding ot relay (Si in that a ground is ap plied from thc armatureand .trout contact o't' relay 59 through aclosedpair' ofcontacts of relay 46, to thV lower(armature. and front Contact ot relay 161. The second mentioned circuit through the line relay 100 causes the operationof relay 61. Relay (5 1 in operating closes an obvious circuit for lighting,r ot signal lamp 31, which thus indicates that lli This relay 64 also closes partially c a circuit of standard character is closed through theother `winding' of line relay `100 and the ring conductor of the circuit for snswering jack 19. An ol rious circuit is also closed by the operation of relay 61 through and front contact of relay 59 so that `when.

these two relays 59 and 61 operate, relays 63 and 64 are operated. The relay 64 in operatingl provides a l cking circuit for itself through its lower winding, armature and :front contact to grouiul at the leftllianal armature and front contact of relay '1".

for relay 66 at its upper inner armature and front Contact, the purpose of which will be hereinafter described. Relay 64 also at its upper outer armature and front Contact closes a circuit for the oper lon of the cut olf relay 101 of the circuit of jack 19 and for the operation of relay 62 over a circuit as follows: battery, through adjustable resistance 'T-l, a pair of closed contacts of key 49, rl-:slstancc 70, upper outer armature and front Contact ot relffry164, closed contact of key windingl of relay 62, closed pair of contacts of keys 44 and 45, the brush and the,corresponiling terminal of switch i sleeve conductor of jack 1, sleeve terminals of jack 1, plug 6, plug 13, `1ack 19, winding of cut-off relay 101 to ground. lhis circuit causes the operation of relays. 62 and 1O1 The operation of relay 62 closes an obvious circuit for the lighting-'of signal lamp V82 which indiuites that a circuit of standard character is closedthrougl'i the cut-off relay 101 and the coiuluctor of the circuits for answering jack 1S). lt should be noted that a tester may observe the lighting of lamp 102 associated with the circuits of jack 19 on the operation of the line relay 100 and the extiir Y gulshiug of this lamp on the operation of cut oil relay 101. the circuits for :uiswcring jack 1S) are now completed and the continuity tests of the circuits for 'the next answering jack in the case, namely, jack 20, may be made.

It should be noted that on the operation of the cut. off relay 101, the circuits for the operation of the line relay and the relays 59 and 61 are open at the right lhand armatures and back contacts of the cut-off relay 101. AThis causesthe release `of line relaylOO and relays 59 and 61 and the releaseof these last two relays causes the release ofrelay 63: The release of relay 63 now closes a circu1t for the advancement of the selector brushes tothe tip,v ring andsleeve terminals for the tip,;ring and sleeve uit y The continuity' tests of conductorsof thesecond circuit,that is, the

circuit for performing thecontinuity tests f vof thev circuits for jack 20. The circuits for this'advance of the selectors maybe traced as follows: The first circuit is closed, due to the release of relay '63 and 1s as follows: battery, lower windingof relay 66, a pair ofl closed contacts of key 49, lower armature and back contact of relay 65, upper inner armature and front Contact of relay 64, armature and back contact Vof relay 63 to ground.V This circuit causes the operationl of relay 66. The operation ofV relay 66 opens the ,energizing circuit for relay 57 at its ymake-before-breakv contacts. v'On the re! lease of relay 57, relay 64 is released which opens the original energizing circuit for relay `66. Relay 66 is, however, maintained operated through its upper winding, upper armature and front contact, make-before- Vbreak contact of relay I67, 'armature and back contact of stepping magnet 41, brush of switch 40, lower armature and front contact of relay 66, a pair of closed contacts of key 50 to ground. The operation'of relay 66thus provides through the closing of its lower armature andfront contact, a circuitfor the operation of stepping magnet 41 as follows :A battery,'winding of stepping magnet 41, the first terminal and brush of switch `40, lower armature and front contact 0f relay 66, a pair: of closed contacts of key 50 to ground. The stepping magnet 41 operates fin this circuit and moves the brushes.

of the switches v to 40 vone step. As the `brush of switch moves from the lirst terminal the selector magnet 41 and relay 66 are released. When this magnet and relay are released the original energizing circuit for relay 57 is again closed through the makebefore-break contact of relay 66 and through theiarmature and back contact of stepping magnet 40 as hereinbefore described.` The continuity tests of the circuits for jack 20 may now` therefore begin through the operation of relay 57 and the tip and ring ,connections for the line relay associated with jack 20 are-closed to operate relaysl 59Yand 60 and the operation ofthe line relay associated with jack 20, followed` by the operation of relays 63 and 64 and the operationof the cut off relay of the circuits for jack 20 and the operation ofrelay 62. l y y The operation of the cut off relay causes, as before stated, therelease of relay V63 followed by the operation of relay 66 and the `advance of the selector switches 35 to 40 to the conductors of thev circuitsA for jack 21."

In'this manner the continuity test of the circuits for succeeding answeringV jacks 21. 22fand 23 are provided for and performed succession. As .these tests are performed it will be noted that lamps l24 to 28 are lighted in succession to indicatetthe particuiur lar answering jack under test at any time. Thisv is accomplished through the brush and corresponding terminals of switch 38, that is, for example, when jack 19 is tested, a circuit will be completed for lamp 24, to battery, lamp 2-l through the first tern'iinal and the brush of switch 3S to ground, and correspondingly, circuits will be closed in succession by lamps to` 28 asl jacksl 20 to 23 are tested.v

If it is desired, to malte the above continuity tests only the key 55 should be operated simultaneously with the operation of key 52 at the beginning of the tests. lf this is the case, the buzzer 78 will operate at the completion of the continuity tests for the circuits of. the last jack in, the group, namely jack 23, in the following manner:l Then the switch has finished the. testing of the circuits of jack 23, the brushes of the switches to Ll0 will be located on the fifth terminal. In this position a circuit will now be closed for buzzer T3 as follows: battery, winding of buzzer 78, left-hand closed con tacts of hey 55, the fifth terminal of switch and its corresponding1 brush, lower armature and` front contact of relay 66, a pair of closed contacts of heyV to grou ud.

The operator hearing the sound from the buzzer 7S will then remove the plugs i3 to Cdl li' fronrjaclis'ltoQB and. insert these plugs in another set of five answering jacks whereupon the contini'iity test of the circuits for these jacks may proceed. 'llo open the circuit for the buzzer and advance the selector switches first to the sixth terminall position and later through the seventh to the eleventh terminal position inv readiness tothe testing of this second set ofanswering jacks, key 5l will now be operated. rthe operation'of this hey closes an obvious energizing. circuit for relay G7 which in operating closes at its lower armature and front contact an obvious energizing. circuit to stel'iping magnet il and relay Gi' provides for itself an obvious locking circuit thr ugh` the armi-dure and back contact of magnet 4l to insure the operation of magnet el. n. the operation ofl relay 67 relay (35 releases andi opcnsthe buzzer` circuit and. onV the opration of magnet 4l the brushes of the switches 35 toll() are advanced to the sixth terminal position. lf the key 5l is now operated five times in succession the relay 67, and consequently, magnet l-jl will operate the corresponding number of times to advance the selector switches until their brushes come to rest in their eleventh terminal position. lt will be noted that in this positionlainp 2l will become lighted, so, that the tester will now know that the continuity test of another setV of tive answering jacks may begin. By virtue of the plugs 'i3 to 17 of the cord l2 beingV insertedin said second. group of answering jacks and the switches being advanced tothe eleventh terminal position, the testing of the circuit for the first of these jacks will. begin as relay 5T was reoperated on the release of relay G7 and the release of magnet ell and the circuits from the tip and ring conductors of this first iaclr will be completed through to the relays 59 to (5l as hereinbefore de ibed. In this manner, two successive sets of live jacks each may lie tested for continuity by shifting the plugs 13 to 17 each time the himw zer i8 is heard from one set of five answering jacks to another and the key 51 has been operated the required number of times between each test of five answeringl jacks each io advance the selector switches 35 to l-f) past terminals 6 'to l0 and lll Vto 30. '.lhcse ferminals 6 to l() and loto il() are normally reserved for the adjustment 'tests of the line relays associated with these two sets of answering iaclf circuits. Such adjustmentwill presently be des crilied.

When the selector' e tches 35 to fl() come to the 20th terminal positions as will be the ccse after two sels of answering jacks have been tested for continuity of jack circuits or when beth continuity andadjustincnt tests have been made.y as will be hereinafter described, the operation of key 5l lwill advance the selector brushes to the 21st position in a manner as hcreiubefore described and when this position is reached the selectors are automatically returned to the normal position shown in the drawing. This is accomplished as follows: In the 21st position a circuit is closed for the operation of relay 57 so that the tip and ring conductors of the test set are connected up from the brushes of switches 35 and 36 tothe relays 59 and 60 and 6l. Ground on the brush oi switch 35 from terminal 2l causes the operation of relays 59 and G0 and the operation of relay (S0 closes an obvious circuit for relay 65. Relay 65 in operating provides a locking circuit for itself to ground at the left-hand armature and front contact of relay 57. This relay 65 also closes a circuit for the operation of relay G6 as follows: battery, lower winding of relay 66, a pair of closed contacts of lzey i9, lower armature and front contact of relay 65, terminal 2l of the brush switch 39 to ground. Relay 6G in operating causes the advance of the selector switches rto ll0 to the 22nd position by closing the circuit for magnet Lil to its lower armature and front iontact and terminal 2l of switch 41.1.. As the switches move from their position 2l to position :illof `these relays are released andiwhen the QQnclposition is reached, the above operations are repeated and the switches thereby returned to normal position.

VIt will be noted that during these continuity tests described `above, the so-called adjustment tests of the cut-off relays are automatically performed, that is, the circuits for the cut vofi'r relays completed through relay lof lli

v.operations will be as follows:

-the line lamp of the associated answering jack circuitsuch failureinay be due to the faulty adjustment of the cut oil'A relay or to some unstandard condition `in thecircuit therefor in the particular".answering jack" circuitunder test. To ascertain the source of such failure in theoperation of the cutoli' relay key 53nxay be operated. By operating this key, `a so-called soak value of current maybe placed through the cut-oli relay winding' by the opening of the circuit for this relay through the adjustable resistance 22 and the yresistance 70 and close connection directly from a lwhirling of the relay 62 to battery at the now closed contacts of key 5?). ticular cut olf -relay now operates it would indicate that the electrical characteristics of the winding of this particular cut ofin relay were at fault. AIf relay 62 does not operate some unstandard'` condition exists in the sleeve conductor leading ,to this cut-oil relay.

If it is desired to perform adjustment tests of 'the line relays of a particular group of live answering jacks connected for test immediately after the continuity tests ofthe circuits therefor ,j and the adjustment tests of `the cut-ofi relays have been performed, the key is not operated with key 52 at the beginning of the tests but allowed to remain in a normal position. lt will be noted that at the completion of the tests oi? the five answering jacks and while the brushes of the vswitches 35 to ll0 are in their lifth position, a circuit will be closed to prepare the set for adjustment tests of the line relays. A circuit for starting these When the brush of switch 10 alights on the fifth terminal, a circuit will be completed for stepping magnet- -ll as follows: battery, winding of fstcjirning magnet 1l1, a normally closed pair of contacts of key 55, fifth terminal and brush of switch 40, lower armature and front Contact of relay 66,Y a'closed pairof contacts of key 50 to ground. The stepping magnet willnow take one additional step and cause the brushes of switches 35 to l.t0 'to contact with their sixth terminals. At the operation of vstepping magnet 41, the holding circuit for relay 66 will be open at the armature and back contact of this magnet, ,thus allowing relay-66 to release and the original energiZingcirCuit for relay 57 is again closed at the normal contacts of the relay 66. ,In` this position, f the circuit for the two windings of the line relay 100 will be completed to the relays 59 and 60 and 61 lint it will noted, that their circuits will be ,aadiately opened and other circuits @ourl 1f this par` resistance 71, font contact of relay 69, adjustabley resistpleted `due vto the operation of relayV 58, under the ,'.cireumstances which takes place over a circuit as follows: battery, winding of relay 58, a pair of closed contactsof key 50, apairof closed` contacts of key 55, the Y 'th terminal `ot" switch 39 and the correponding brush to ground. The operation of relay 58 opens the energizing circuit for reiy 57 which in releasing opens .the tip and g conductors fromthe line relay :100 tothe relays 59 and 60 and k61 and relay 58 closes a loop lcircuit from the windings Ofline relay 100 through the adjustable resistances k71` and 72 as follows: battery, rightfhand winding of line relay 100, outer right-hand armature and back contact of cut-ofi1 relay,v 101, tip terminals of jack 19, plug 13, plug v6, ack 1, sixth terminal of switch 35 and the corresponding brush, a pair of closed con! tacts of key 46, outer right-handarmature and front contact of relay 58, 'adjustable right-hand arma-ture .and

seV

ance 71, a pair of closed contacts of vkeys eiland inner right-hand armature and front contact of relay 58, a pair of closed contacts of key 46, the brush of switch 36 and it-s sixth terminal to the tip and ringtermi nals of jack 1, plug 6, plug 13, jack 19, right-hand inner armature andback Contact of relay 101, left-hand winding of relay to ground. However, it should be noted that this circuit is not completed until relay 69 `is operated vwhich takes place imme* `tely upon the operation of relay 58. rEhe circuit for the operation of relay 69 icas` follows; battery, winding of relay 69,' a

.closed pair of contacts of key d8, left-hand armature and back contact of relay 68, middle right-hand armature and front contact of relay 58 to ground; The resistances Z 1 and [2 are adjust-ed to cause theproper electrical condition to prevail on the tip and ring` conductors forjthe operation of line relay vrelay releases7 the relay 68 released and again closed the circuit for the operation Y guished to indicate the operation and release 9i? the lie@ valere Br the' Pieper adjust* ments 'ot the resistances 7l and 72 therefore, the operating and release values of the line relay 100 will be tested. By arranging the adjustment tests ot the line relays so that the line lamps are alternately lighted and extinguished, a distinction is made between these tests and the continuity tests.

lt should be noted that due to the 'fact that the relay 6G is not operated in this circuit, the selector switches 35 to 40 will not advance for the adjustment tests ot the succeeding jacks in the group of jac is connected to the test set but that the selector may be adif'anced for the testing oit these succeeding jack circuits by the manual operation of key l. The operation oit this key closed an obvious circuit tor the operation of relay 67. The operation of this relay closed an obvious circuit t'or the magnet 4l to advance the selectors to connect the set with the circuits of the next answering jack, in this case jack 20. When now, therefore, the brushes of these switches are advanced to the seventh terminal, the circuit for relay 58 will be again closed as pre viously traced except that the ground will now be supglied through from the brush ot switch 39 at its seventh terminal. In a similar manner the line relays ot the succeeding answering jacks are tested, that is,V

each time key 5l is operated, the brushes ol'l the selector switches to 40 will advance the connections to a succeeding answering jack. When the fifth answering jack has been tested, a circuit will be closed for the operation of the buzzer 71 as follows: battery, winding o1 the buzzer 7l, righthand armature and front contact ol relay (S8, tenth terminal ot switch 38 and its corresponding brush to ground to indicate thatthe adjustment test of the line relay ot the tive answering jack circuits has een completed.

It' it is desired to test the actual operating value ot a line relay, trat is. in a line relay does not operate on the proper :'uljustment ot resistanees 7l and 72, the pointers 7 5 may be moved toward the right until a connected line relay does operate. To permit this to be done, :1 key 47 will be operated. llfhen this key is operated a circuit is closed for the operation of relay 5S as follows: battery, winding ot relay 58, outer right-hand closed contact of key 47 to ground. The operation oit relay 58 closes the test circuit from a line relay through the resistances 7l and 72 as hereinhefore described, and a circuit is also therefore closed lor the operation ot' relay 69 as teh lows: battery, winding oi relay 69, a pair of closed contacts of key 48, outer letthand pair or closed contacts of'key 47 to ground. The circuitfor the line relay to be thus tested is also closed through the operation ot' key 47 to the inilliammeter .74

lolloifs.' from resistance 73, lett-hand inner closed contacts of key 47, a- `pair o closed contacts of key through to the inilliammeter 73, a pair of closed contacts olf key 49, apair of closed contacts of key 5G, inner rightshand closed pair of'contaets ot key .-7, a pair of closed contacts of key 48, inner rigllt-hand armature and front contacts ot relay 58 so that when the slider is moved toward the right and the line relay under test operates, the exact value otl the current passing through this relay is registered on the milliammeter 74. That is, the actual operating'value of any line relay under test may be meas red in this manner.

Similarly, if it is desired to test the actual release value olE any particular line relay, the key may be operated. In this case relay 38 will be operated through an obvious circuit through the closed outer righthand contacts of key 48 and relay 65) will be prevented from operating through the opening ol the outer left-hand contact oit key 48 so that the loop circuit will be open through slider 75 but closed through the slider 7 (l which may now be moved to the left until the particular line relay under testreleases. lt should also be noted that the operation ot key 48 closes this loop circuit tor the line relay through the milliammeter 74 to measure the actual Value of the current at the time the line relay releases, The circuit of this loop to the milliammetcr 74 may be traced as follows: resistance 7l,

a pair of closed contacts of key 47, inner lett-hand closed contacts of key 48, a pair of closed contacts of key 5U through the milliammeter 74, a pair of closed contacts ot key 49, a pair of closed contacts of key 56, inner left-hand closed eontacts'otI kei,v to the inner right armature and front contact of relay It it is desired to measure the actual operatingvalue of any particular eut-olf relay, key 49 may be operated. In this case, the Vcircuit from the cut-off relay will not ,flo through resistance 70 but .may be traced from the battery, through the adjustable resistance 73, right-hand inner closedicontacts ol' key 49, a pair of closed contacts of key 56 through the milliammeter 74, a pair ot closed contacts of key 5G, inuer left-hand closed contacts ot key 49, the closed contacts ot key 53, winding of relay 62 and out through the windingof the particular cut oil relay under test as hereinbefore traced to ground. The slider 7 6 may now be moved across` the resistance 73 until the cutott1 relay connected in this circuit operates and the opera-ting value of the current Howing in the circuit may be noted on the milliammeter 74.

The purpose et the key 56 in the circuits above mentioned to the milliammeter 74 is for the purpose of reversing the current How ffl lll() Vdifferent types of through the meter in case 'the connections f ,particular jack circuit does not function properly the tests oi' any one otthese circuits may be repeated by operating key'O .at the time the unstandard condition` is observed. The operation ot key 50 closes an obvious circuit for the operation of relay 57. This relay in operating completes a circuit for the particular jack circuit under test through to the relays 59 and 60 and 6l and the operation of the test circuits are repeated in the saine manner except for thecircuit :tor thev advance ot the selector switches nornially completed through the lower armature and front contactof relay 66 and that is in this case opened at the outer lett-hand contacts oit key 50. When, therefore, relay 66 operates onthe release otrelay 63, the selectorswitches are notadvanced. Relay 57, however, is released as under normal conditions in the operation of relay 66 causing the release of relay 64 which in turn, causes the release of relay 66 to again complete the circuitor relay 57. Y In this manner thetest 'for the particular jack circuiton which an unstandard condition has been observed is repeatedtiine and again until key 50 is releasedat which time the tests of the succeeding jack circuits may proceed in the usual manner. i

' Y The unstandard conditions above referred to that may occur during the continuity testing of jack circuits and adjusting tests of cut off and line relays maybe dueto various causes. For example, the electrical condi tions on the tip conductor of a jack circuit may be such as to cause the marginal relay 60 toopei'ate in series with relay 59. The marginal characteristics of relay 60 may be such as to prevent its operation Von currents through the tip conductor circuits below a certain predetern'iined value. This value may be the maximum allowable for tip conductor circuits through linerelays and in this manner wheneverrelay 60 does operate it will be known that the current through the particular tip conductor through the line relay under test is excessive.' If relay 60 operates, an obvious circuitpis closed for the operation of relay 65"which in turn closes an obvious circuit for the lighting of lamp 63V to indicate this unstandard condition. Relay 65 locks to relay'57. It should be noted that under these circumstances the k'switches will not advance at the completion ation otrelay 66, onlthe ,releasefvot relay 63,

Other unstandard conditions maybe that V.inlays 59and 61 fail toiopeiate altogether or tail ,to release when the-cut-olf i'ielayoit jack circuit under ytestoperates.` In these s thercircuit' for the operation oit relay.

the

66 'will not4 be completed so that the selector switches will `not advance and the signalv lamps 30,31, and '32 will'then indicate the` exact `condition Orrauseot failure oi the jackacircuit..under test` c For example, ,if

.lamps 30 and Slt-ail to light, this will indicate that either the tip and ring conductors reversed 0r that they aie open. If lamp 30 lighted and lamp 3l fails to light, this will indicate that the ring conductor is open, it lanipfl()v failsto light and lamp 31 is lighted, this will indicate that the Vtip condi; 'lior is open. To ascertain if the tip. and rng conductors are reversed vkey 43 may be operated and it. lamps 30 and 3l' then light, it `int icates a reversalrot these conductors, lt. lamps 30 and 3lare lighted and lamp l2 fails-to light, this will` indicate that the sleeve conductor is open. I the lamp 32 and lamps 30 'or 3l arel lighted, this will indicate that the cutoff relay has failed to open the tip or ring conductors." It the key 523 isthcn operated and lamp 32 'and lamps "30er 3l are lighted, this will indicatethat there is a `f g'roun'd on the sleeve conductor ou that there is a. talsezground or battery on ,.tlietipi conductor 0r the ring conductor. If

the lainpBQ and lamp 33 are lighted, this will indicate that there is a ground betweenthe cut off relay andthe line relay on the tip conductor.V lWhen the lamps 3.0, 32 and are lighted, this will indicate that there is a ground between the answeringjack itself and the cut-od' relay on the tip Vconductor. It it is thought that the ring and sleeve conductors are reversed key 4:4 may be operated, and if the test then proceeds. in the regula-r manner,itindicates that the analysis was correct. Similarly `it it is tlimight that the tip and sleeve conductors are reversed Athe key 45 may be operated' and Vif the test then proceeds in the regularmanner, it indi.-

.catesfthat the analysis in this-respect was correct. It will thus be seen that by these various coinl'iinations of signals and by the manipulation ot' the reversing keys as -described above, the exact conditionk ot a particular answering ack circuit under test may be indicated.

It it is desired to test any ene of the answering jack circuits to tieexclusion of all others, key 5l may be operated a number of times until the selector switches havebeen advanced to the jack circuit it is desired to test, which will be indicated by the lighting of a particularone ot the lamps 24 to 28, corresponding to the j ack circuit to'be tested. It then the start key 52 is operated, the test` ing of this circuit may lbegin and if the key llO is also operated, the testing of this circuit lmay be repeated.

It should be noted that the handles or holders 11 and 18 may be equipped with push buttons 8O and S1 connected in'an obvious inannerto cause the operation of relay G7 if either one of these buttons are depressed to close their contacts. These buttons, therefore, serve the same purpose as key 51 and it is readily seen from the above description of the various manipulations of key 51 that it is of a decided advantage to have an arrangenfient of this sort. These manipulations may be controlled from the handles of the multiple plugs, i. e., by this arrangement quick advancement of the switches may be made when the adjustment tests of the line relays are carried on and also when it is desired to test a particular jack circuit to the exclusion of the others.

This testing set is also arranged for testing other types of answering jack circuits beside the standard type referred to above, such as the kind in which direct ground is connected to the tip conductor. One circuit of this type is shown in Fig. 3. Another type of jack circuits that may be tested is the kind in which the connected subscribers line is equipped for coin collecting service. One of these last types of circuits is shown in Fig. 4.

If a test is to be made on the type of ,circuit shown in Fig. 3, the procedure is the same as for the standard jack circuit except that key 42 is operated. In this case, therefore, the closing of the righthand contacts of key 42 includes a resistance 82 to ground in parallel with the winding of relay 6l so as to provide suflieient current flow through the ring conductor of the jack circuit under test. to cause the line relay 300 to operate, as it will be noted that in this case both wind ings of relay 300 are connected in parallel from battery to the ring conductor. As there is a direct groundA on the tip conductor, both relays 59 and 60 will operate on this test. The operation of relay 60 causes the operation of relay 65. This lamp 38 is, however, not lighted as the circuit therefor is opened at the right hand contacts of key 42. The closed left hand contacts of key 42 provide a connection as shown between the two leads opened by the lower armature and back contact of relay so that the cir- 'cuit of the test set will operate in the same manner as in the original test, i. e., when relay 63 releases the selector switches will he advanced to the next jack circuit through the operation of relay 66, through the circuit closed, therefore, at the above mentioned closed contacts of key 42.

If jack circuits of the other type shown in Fig. 4 are to be tested the operation of the test set is identical with the functions when an lordinary jack circuit is tested eX- Vcept that `in this case the key 46 will be operated to cause the circuit to function properly. The operation of this key rcverses the tip and ring conductors, for it will be noted that the tip conductor in this type of jack circuit is connected to battery through a winding of the line relay while the ring conductor is not connected through the line relay but directly to the subscriber station. Hence, in performing a continuity test only relay 61 will be operated as relasy is not connected in any circuit. Therefore, to cause the operation of relay 64 which formerly received its ground through the operation of relay 59, a connection for this relay is now closed directly to ground through a pair of left hand contacts of key 4G so that the test will proceed in the regular manner to advance the selector switches from one jack circuit to another. In performing adjustment tests of the line relays in this type of jack circuits there is provided, due to the closed outer left hand coni tacts of key 46, a ground connection through a compensating resistance 83 for the circuit through the line relay under test, through the tip conductor and the adjustable resistances 711 and 72. A ground at key 46 also puts the relay 65 under control of relay 59 in this case so that if a ground is present on the ring conductor of any of the answering jack circuits tested, the relay 59 by being transferred to the ring conductor by key 4G will operate and thus cause the operation of relay G5 to prevent the switches from advancing for the testing of the next jack circuit until this unstandard condition is noted by the tester.

rlhe procedure in testing the operation of the test set itself is as follows: The jacks to 94 may for that purpose be connected, respectively, to jacks l to 5 by means of the cord l2 and the functions of the set when a continuity test is made, are tested through the operation taking Yplace due to the connection of the artificial line to the jacks 90 and 91. To start testing the keys 52 and are operated. It is readily seen that the relays 59 and 60 and 63 will operate through their respective tip, ring and sleeve conductors of jack 90 as the battery and ground are connected over the tip and ring conductors through suitable resistances simulating the windings of the `line relay while the sleeve conductor is connected through the cut-olf relay to ground. In this manner the circuits used for the continuity tests in the test set itself are tested and as the selector switches will advance two steps the functions of the stepping magnet 4l and its associated circuits are also tested as the artificial line connections are the vsame for jack 91 as they were for jack 90. If, therefore, the test set circuits are functioning properly, lthe testset should respond as if two successive jack `circuits connected to jacks 1 and 2 are tested and the switches should advance to test jack 92. In this the third position, however, it will he noted that theartificial liue circuit connections for ack 92 is such as to simulate a ground on the tip conductor of a jack tested between the canori relay and the line relay, i. e, Va ground is connected through acomparatively lov.Y resistance 9S to the tip conductor, causing relays 59 and G0 to operate and thercircuits to function as hereinhefore described when an unstanda-rd condition of this lrind occurs. In other Words, the operation of the marginal relay GO and relay tested in this position. It now the lrcy 5l is operated to advance the switches to the /l-th position as to cause test to he made through the jack 93, in this position the ring and sleeve conduetors of the jaclr 93 are connected as under normal conditions While the tip conductor is so connected as to simulate a condition ivhere it `is not hrolren loy the opera tion of the cut oli4 relay. In' this case lamps 30 and 32 remain lighted at the saine time. It the switches are non' advanced to the 5th position, i. e. to cause tests to he made over jack 94, it Will he that the ring conductor oi' this jack is nothrolren hy the operation oi the cut oil'l relay 95 so that the lamps 3l and 32 are lighted at the time. If

tests like these are made on the test set itself it may he inferred that the functioning oi the setwhen used Will he satisfactory.

that is claimed is: K

l. In a system tor testing telephone circuits, means lor temporarily and simultaneously connecting a t p' device to plurality ot telephone circuits, means for automatically and successively testing said circuits characterized in tV provided :tor deterniining` if the current through line relays ci ated with said circuits is ahove or heloiv certain value and in this that means is provided for preventing the advance oi the automatic testing from vone circuit to another responsive to a condition set up .in the testing device when the current through a line relay under test ishelou7 said certain value and in this that means is provided `for indicating when said last mentioned condition exists.

2. In a system for testing telephone cir- .,s that means is cuits, means comprising a. plurality of plug-v ending cords with the plugs at each endassemhled in a common handle :tor temporarily and simultaneously connecting the testing device to a plurality of telephone cir cuits, means for automatically and simultaneously performing certain tests upon said circuits, and means operative from either of said handles for performing other tests upon said circuits.

3. In a system for testing telephone circuits, means iior temporarily and simultaneously connecting a testing device to a plurality telephone circuits, means for autoinatically and successively performing certain tests upon said circuits, means for manually performing certain other tests upon saidrcircuits, and means for indicating when the ahove mentioned tests ot all of the telephone circuits have heen pel ernied.

e. In a system for testing telephone circuits, means for temporarily and siniultaneously connecting a testingV device to a plurality ot' telephone circuits, means for auto* matically and succ s vely performing eertain tests upon said circuits, means manually performing certain other tests upon said circuits., means for indicating' When Veither et said types of tests is in progress,

and means ior indicating When said second nentioned type ot' tests is completed.

5. In a system for testing telephone circuits, means or temporarily and simultaneously connecting a testing device to a plurality ot telephone circuits, means for automatically and successively performing cer tain tests upon said circuits, means for manually performing certain other tests upon said circuits, and means `whereby said' testing device may itself he tested, said last mentioned means characterized hy the provision ot means 'lior testing the normal `functions ot' the testingdevice and by the provision of means for simulating unstandard conditions such as may lloe encountered during the operation ot the testing device and for testingthe device under such circumstances.

In Witness whereof, Wehereunto subscribe our names this 14th day of January, A. D. 1926. JOHN WLVAN DE WATER. BERT R. BLAIR. 

